Solid state watch display switch

ABSTRACT

Disclosed is a solid state wristwatch with an electro-optical digital display of light-emitting diodes. Incorporated in the watch is a switch for actuating the display in response to a predetermined movement of the wearer&#39;&#39;s arm so that movement of the other hand or arm is not required and the other hand is left free for carrying packages or other uses.

United States 1 Patent [19 Bergey 4 1 SOLID STATE WATCH DISPLAY SWITCH [75] lnventor: John M. Bergey, Lancaster, Pa.

[73] Assignees HMW Industries, Inc., Lancaster,

[22] Filed: Jan. 14, 1972 [21] Appl. No.: 217,765

Related U.S. Application Data [63] Continuation-impart of Ser. No. 138,557, April 29,

[52] US. Cl. 58/50 R, 58/23 R [51] Int. Cl G04b 19/30, B04c 3/00 [58] Field of Search 58/23 R, 34, 50 R,

[56] References Cited I UNITED STATES PATENTS 4/1971 Walton 58/23 R X 4/1964 Fiechter 58/23 R X [111 3,742,699 [451 July 3,1973

3,025,665 3/1962 Dock et a1. 58/144 3,643,418 2/1972 Polin et al.... 58/85.5 X 3,171,245 3/1965 Breed 58/144 3,485,033 12/1969 Langley 58/50 X FORElGN PATENTS OR APPLICATIONS 2,017,788 4/1970 Germany 58/50 R Primary ExaminerRichard B. Wilkinson Assistant ExaminerEdith Simmons Jackmon Att0rney-R0bert E. Leblanc, Leonard F. Stoll et a1.

[57] ABSTRACT Disclosed is a solid state wristwatch with an electrooptical digital display of light-emitting diodes. Incorporated in the watch is a switch for actuating the display in response to a predetermined movement of the wearers arm so that movement of the other hand or arm is not required and the other hand is left free for carrying packages or other uses.

13 Claims, 11 Drawing Figures PATENIEDJUL' 3 I91; SHEET 1 3 3,742,699 I FIG. 4

5 INPUT MIN, HR 4 DIVIDER READ SET SET FI G.5

PAIENIEBJUU Ian 3,742,699

SIEET 3 BF 3 FIG; II S 208 2l2 L OUTPUT (1/ M08 SWITCH SOLID STATE WATCH DISPLAY SWITCH This application is a continuation-in-part of copending United States patent application Ser. No. 138,557, filed Apr. 29, 1971.

This invention is directed to a solid state watch having an electro-optical display and, more particularly, to an improved switching arrangement for the display. In the present invention, the watch incorporates an armactuated switch which is operated when the wristwatch is moved with the arm of the wearer into a predetermined position or in a predetermined manner.

This invention relates to a solid state timepiece and, more particularly, to an electronic wristwatch which employs no moving part. In the present invention, a frequency standard in the form of a crystal oscillator acts through solid state electronic circuit dividers and drivers to power in timed sequence the light-emitting diporates a read switch/magnetic setting arrangement.

Battery-powered Wristwatches and other small portable timekeeping devices of various types are well known and are commerically available. The first commerically successful battery-powered wristwatch is of the type shown and described in assignees U.S. Pat. No. Re. 26,187, reissued Apr. 4, 1967, to John A. Van Horn et al. for ELECTRIC WATCH. Electric watches of this type employ a balance wheel and a hairspring driven by the interaction of a current-carrying coil and a magnetic field produced by small permanent magnets.

ln recent years, considerable effort has been directed toward the development of a wristwatch which does not employ an electromechanical oscillator as the master time reference. In many instances, these constructions have utilized a crystal controlled high frequency oscillator as a frequency standard in conjunction with frequency conversion circuitry to produce a drive signal at a suitable timekeeping rate. However, difficulties have been encountered in arriving at an oscillator/frequency converter combination having not only the required frequency stability but also sufficiently low power dissipation and small size to be practical for use in a battery-powered wristwatch.

In order to overcome these and other problems, there is disclosed in assignees U.S. Pat. No. 3,560,998, issued Feb 2, 1971, a high frequency oscillator type watch construction using low power complementary MOS circuits. The oscillator/frequency converter combination of that patent is described as suitable for driving conventional watch hands over a watch dial or, alternatively, for selectively actuating the display elements of an optical display in response to the drive signal output of the converter.

ln assignees U.S. Pat. No. 3,576,099, issued Apr. 27, 1971, there is disclosed an improved watch construction in which the optical display takes the form ofa plurality of light-emitting diodes which are intermittently energized on demand at the option of the wearer of the watch. This assures a minimum power consumption and an increasingly long life for the watch battery. An improved watch construction of this general type incorporating solid state circuits and integrated circuit techniques is disclosed in assignees copending U.S. Pat. application Ser. No. 35,196, filed May 6, 1970 now U.S. Pat. No. 3,672,155.

The present invention is directed to an improved watch construction of the same general type as disclosed in the aforementioned application and patents and one which utilizes no moving parts to perform the timekeeping function. The watch of the present invention consists of three major components, namely, a quartz crystal time base, a miniature time computer module, and a power supply or battery. These microminiature components are packaged in a conventional sized wristwatch chassis or case. The tiny quartz slab is precisely cut to predetermined dimensions so that it vibrates at 32768 Hz when properly stimulated by pulses from an electronic oscillator. The high frequency from the crystal time base isdivided down to 1 pulse per second by utilizing a multistage integrated circuit binary counter. The time computer module counts the pulse train, encodes it into binary form, and then decodes and processes the result so as to provide the appropriate signals at display stations.

Situated on the front of the watch adjacent the display is a pushbutton demand switch which, when depressed, instantly activates the appropriate visual display stations. Minutes and hours are programmed to display for one and one-quarter seconds, with just a touch of the demand switch. Continued depression of this switch causes the minute and hour data to fade and the seconds to immediately appear. The seconds continue to count as long as the wearer interrogates the computer module. Computation of the precise time is continuous and completely independent of whether or not it is displayed.

The watch display consists of a television screen-like colored filter which passes the cold red light from gallium arsenide phosphide (GaAsP) light-emitting diodes. Preferably, a seven segment array forms each individual number (except for the hours tens station) at thee appropriate moment at a brightness determined by a specially constructed dimmer or display intensity control circuit. This dimmer circuit utilizes a photodetector to measure ambient lighting conditions so the display intensity provides viewing comfort under all day or nighttime lighting conditions.

An important feature of the present invention is the incorporation in a watch of this type of a switch for energizing the display diodes in response to a predetermined movement of the wearers arm on which the wristwatch is mounted during normal operation. In one embodiment, the arm-actuated switch is used as the sole demand switch for actuating the display, whereas in the preferred embodiment the arm-actuated switch is provided as an alternative to the conventional demand switch, also incorporated in the watch.

As is well known, light-emitting display diodes at the present time typically consume relatively large amounts of current when they are activated. Because of this, it has been found desirable to readout from the watch the displayed time only upon interrogation by the wearer. For this purpose, the watch has incorporated a demand switch actuated by a demand button on the face of the watch so that the time is displayed and the diodes energized only when the demand button is depressed. The demand button is most conveniently operated by the thumb or finger of the wearers other hand, requiring freedom of the wearers hand in order to depress the button. In some instances, such as when the wearer is carrying packages or objects in his other hand, depressing of the demand button in order to ascertain the time may be inconvenient.

In order to over this difficulty, the present invention incorporates in the wristwatch, preferably in addition to the conventional demand switch, an arm-actuated switch which causes the display to be illuminated and the time to become visible in response to a predetermined movement of the wearers arm on which the wristwatch is mounted. In one embodiment of the present invention, the arm-actuated switch takes the form of an inertial switch operated by a short quick motion of the arm in opposing directions in a plane essentially horizontal to the watch face. In a second embodiment, a force-actuated switch is provided which operates in 1 response to an upward movement of the hand or arm in a direction perpendicular to the plane of the watch face. In another embodiment, the display is provided with a magnetic switch and a permanent magnet is attached to or made a part of the wearers clothing, such as for example a permanent magnet is embedded in a belt buckle. When the wearer wishes to observe the time, he simply draws his arm containing the watch into contact or close proximity to the permanent magnet. In still another embodiment of the present invention, the watch is provided with a capacitive switch actuated by a change in ambient capacitance brought about by moving the switch contained on the exterior surface of the watch away from the wearers skin into proximity of the wearers body. In all instances, the armresponsive or arm-actuated switch is constructed and positioned to insure that a deliberate action will cause I the switch closure, but at the same time to minimize inadvertent actuation of the switch by activity which one would experience during normal routine functions.

It is therefore one object of the present invention to provide an improved electronic wristwatch.

Another object of the present invention is to provide a wristwatch which utilizes no moving parts for performing the timekeeping function.

Another object of the present invention is to provide a solid 'state wristwatch incorporating an arm-actuated switch for the watch display.

Another object of the present invention is to provide a solid state watch having both a demand switch and an arm-actuated switch.

Another object of the present invention is to provide a solid state wristwatch in which the display is actuated by an inertial switch.

Another object of the present invention is to provide a solid state wristwatch in which the display is actuated by a force-responsive switch through operation of the wearer's wrist.

Another object of the present invention is to provide a solid state wristwatch in which the watch display is actuated by a magnetic switch in response to move ment of the wearer's wrist.

Another object of the present invention is to provide a solid state wristwatch in which the watch display is actuated by a capacitive or resistance switch.

These and further objects and advantages of the invention will be more apparent upon reference to the following specification, claims, and appended drawings, wherein:

FIG. 1 is a front or plan view of a wristwatch constructed in accordance with the present invention;

FIG. 2 is a simplified block diagram illustrating principal components of the wristwatch of FIG. 1;

FIG. 3 is a detailed circuit diagram of portions of the electrical circuit of the wristwatch of FIG. 1;

FIG. 4 is a plan view, similar to FIG. 1, of a modified embodiment of the wristwatch constructed in accordance with the present invention;

FIG. 5 is a partial circuit diagram corresponding to FIG. 3 for the embodiment of the wristwatch illustrated in FIG. 4;

FIG. 6 illustrates an arm-actuated inertial switch incorporated in the wristwatch of either FIG. 1 or FIG.

FIG. 7 is a circuit diagram showing the manner of operation of the inertial switch of FIG. 6;

FIG. 8 shows a wrist-operated force-responsive switch for the wristwatch of either FIG. 1 or FIG. 4;

FIG. 9 shows a magnetic reed switch for the wristwatch of either FIG. 1 or FIG. 4;

FIG. 10 illustrates diagrammatically a capacitive switch incorporated in the wristwatch of either FIG. 1 or FIG. 4; and

FIG. 11 is a circuit diagram illustrating the manner of operation of the capacitive switch of FIG. 10.

Referring to the drawings, the novel watch of the present invention is generally indicated at 10 in FIG. 1. The watch is constructed to fit into a watch case 12 of approximately the size ofa conventional mans wristwatch. The case 12 is shown connected to a wristwatch bracelet 14 and includes a display window 16 through which time is displayed in digital form as indicated at 20. Mounted on the case 12 is a demand switch pushbutton 18 by means of which the display 20 may be actuated when the wearer of the wristwatch l0 desires to ascertain the time.

In normal operation, time is continuously being kept but is not displayed through the window 16. That is, no time indication is visible through the window and this is the normal condition which prevails in order to conserve battery energy in the watch. However, even though the time is not displayed through the window 16, it is understood that the watch 10 continuously keeps accurate time and is capable of accurately displaying this time at any instant. When the wearer desires to ascertain the correct time, he depresses the pushbutton 18 with his finger and the correct time is immediately displayed at 20 through the window 16. The hours and minutes are displayed through the window 16 for a predetermined length of time, preferably l l/4 seconds, irrespective of whether or not the pushbutton 18 remains depressed. The exact time of the display is chosen to give the wearer adequate time to consult the display to determine the hour and minute of time. Should the minutes change during the time of display, this change is immediately indicated by advancement of the minute reading to the next number as the watch is being read. If the pushbutton 18 remains depressed, at the end of 1 and 1/4 seconds, the hours and minutes of the display are extinguished, i.e., they disappear, and, simultaneously, the seconds reading is displayed through the window 16. The advancing seconds cycling from 0 to 59 continue to be displayed through window 16 until pushbutton switch 18 is released.

' FIG. 2 is a simplified block diagram of the principal components of the watch 10 of FIG. 1. The circuit comprises a time base or frequency standard 26 including a piezoelectric crystal to provide a very accurate frequency such that the frequency standard or oscillator oscillates at 32,768 Hz. This relatively high frequency is supplied by a lead 28 to a frequency converter 30 in the form of a divider which divides down the frequency from the standard so that the output from the converter 30 appearing on lead 32 is at a frequency of 1 Hz. The frequency converter 30 preferably comprises a binary counting chain of complementary MOS transistors of the type shown and described in assignees US. Pat. No. 3,560,998, the disclosure of which is incorporated herein by reference. The 1 Hz signal is applied by lead 32 to a display actuator 34 which, in turn, drives the display 20 of the watch by way of electrical lead 36.

FIG. 3 is a circuit diagram of the watch 10 of the present invention with like parts bearing like reference numerals. Integrated circuit portions of the watch are illustrated by the large block 70. This block may be formed of several integrated circuit chips, but in the preferred constructions, the large block 70 is formed of a single chip. In any event, it is understood that all the components within block 70 are formed by large-scale integrated circuit techniques.

In addition to the integrated circuit 70 in FIG. 3, the watch comprises a battery 72 which, by way of example only, may comprise a 3 volt wristwatch battery or two conventional l-l/2 volt wristwatch cells connected in series. Connected to the positive side of the battery is a resistor 73 and the battery energizes the time display, generally indicated at 38, which is shown in FIG. 3 as consisting ofa pair of hours stations comprising the digits station 74 and the tens station 76 and a pair of combination minutes and seconds stations comprising digits station 78 and tens station 80. Stations 74, 78, and 80 in the preferred embodiment of the display each take the form of a seven bar segment array of light-emitting diodes, preferably formed of gallium arsenide phosphide which emit light when energized in the visible red region of the spectrum. While a seven bar segment display is preferred, it is apparent that other type displays, such as a27 dot matrix display,may be used.

In addition, the display 38 includes a pair of colon dots 81, each formed by a single light-emitting diode. The display stations are energized from integrated circuit 70 connected to battery 72 by way of a plurality of leads 79. The circuit is completed from the leads 79 to the anodes of the light-emitting diodes and the cathods of the light-emitting diodes are individually connected to the other side of the power supply through strobbing or switching N-P-N junction transistors 82, 84, 86, 88, 90, and 92. There is a separate lead 79 for the total number of bar segments in a display station. That is, with a seven bar segment display, there are seven leads 79, each one connected to a separate bar segment of each station as more fully described below. However, all the cathodes of each station are connected in common through the N-P-N junction transistor for that display. There are two bar segments 94 and 96 for the hours tens display station 76 and they have their cathodes connected to transistor 82 as do the colon dots 81. All cathodes of the hours units station 74 are connected to transistor 84. Display stations 78 and 80 are used to display both minutes and seconds so that station 80 has the cathodes of all diodes connected to transistor 86, referred to as the minutes transistor, and

to transistor 90, which acts as the seconds transistor. Similarly, all the diode cathodes of display station 78 are connected to a minutes transistor 88 and a seconds transistor 92. These transistors have their bases returned to the integrated circuit through current limiting resistors 98, 100, 102, 104, 106, and 108, the emitters of the transistors being connected in common to ground, i.e., the negative side of the power supply battery 72, as indicated at 110.

The anodes of the bar segment diodes are energized from bipolar driver transistors illustrated in FIG. 3 as the P-N-P junction transistors 112, 114, 116, 118, 120, 122, and 124. Since the greatest number of bar segments at any display station is seven, there are seven driver transistors and seven leads 79. The transistor collectors are connected to the display diodes through individual ones of current limiting resistors 126 and the driver transistor bases are connected to the integrated circuit 70 through protective resistors 128. The emitters of the driver transistors are connected in common as at 130 to the positive side of power supply battery 72.

Components of the oscillator 26 in FIG. 3 external to the integrated circuit 70 are the crystal 64, the variable capacitor 66, bias resistor 62, and 7r network capacitors C and C The remaining portions of the oscillator are incorporated in the integrated circuit 70 of FIG. 3. For a detailed description of the preferred embodiment of the oscillator, reference may be had to assignees copending US. Pat. application Ser. No. 143,492, filed May 14, 197 l the disclosure of which application is incorporated herein by reference.

Also external to the integrated circuit is a demand or read switch 132 which is closed when the button 18 of FIG. 1 is depressed. Further manually operated switches external to the integrated circuit 70 are minute-set switch 134 and hours-set switch 136. These switches are connected across battery 72 from the positive side of the battery to ground through respective series resistors 138, 140, and 142. The resistors associated with these switches are used in order to ground the corresponding inputs, otherwise the corresponding inputs would be floating and could be anything. When closed, the switches are used to switch the input voltages from ground to plus.

In the watch of the present invention, the intensity of the light emitted from the display diodes is varied in accordance with ambient light. That is, the diode light intensity is increased for greater contrast when the ambient light is bright, such as during daytime display, whereas the intensity of the light from the diodes is decreased when ambient light decreases. The automatic display intensity control circuitry is generally indicated at 144 in FIG. 3 and comprises a photosensitive resistor 146 suitably mounted on the face of the watch connected to the positive side of battery 72 and to a resistor 148 and capacitor 150. These components are connected to the positive side of the power supply through series resistor 152. Other external components connected to integrated circuit 70 include an internal information lockout lead 154, a transmission gate control lead 156, and an optional input of continuous display lead 158, all normally grounded. A further connection to ground is through resistor 157 and the integrated circuit 70 is also provided with a carryout lead and terminal 159.

For a detailed disclosure of the elements making up integrated circuit 70 and the operation of the watch circuitry illustrated in FIG. 3, reference may be had to the previously mentioned copending U.S. Pat. application Ser. No. l43,492, filed May 14, l97l, incorporated by reference. Briefly, the oscillator 26 under the control of piezoelectric quartz crystal 64 produces an output I signal having a frequency of 32,768 Hz. This is divided down by the frequency converter 30 incorporated in integrated circuit 70 in the form of a binary dividier chain to a frequency of 1 Hz. The dispay actuator 34,also partially incorporated in the integrated circuit 70, decodes and converts these signals into a form suitable for driving a display which timing signals are applied through resistors 128 and bipolar driver transistors 112, 114, 116, 118, 120, 122, and 124 as timeindicating signals to the anodes of the display diodes of the display stations. The intensity of the light from the display diodes is controlled by the photosensor 146 mounted on the face of the watch in response to the intensityof ambient light. In order to conserve energy from the watch battery, not all stations are energized at the same time. To this end, strobing signals are developed at the integrated circuit terminals S S S S S and S, and these are applied to the strobe transistors 82, 84, 86, 88, 90, and 92. When the demand button is first depressed, the hours are displayed on stations74 and 76 and the minutes of time are displayed on stations 78 and 80. After 1 H4 seconds, these stations are extinguished and if the demand button remains depressed, stations 78 and 80 then display the seconds of time as long as the demand button remains depressed. It is thus seen that stations 78 and 80 serve to display both minutes and seconds. The strobing outputs are such that the sequence of the display is as follows: (a) tens of hours and colon, (b) units of hours, (0) tens of minutes, (d) units of minutes when the demand button is first depressed or, if it remains depressed after one and one-quarter seconds, (a) nothing, (b) nothing, (c) tens of seconds,,(d) units of seconds, and in either event the cycle then repeats.

An important feature of the present invention resides in the fact that the watch is provided with an armresponsive switch 160 connected in parallel with the demand switch 132 as illustrated in FIG. 3. Switch 160 is normally open but closes in response to a predetermined movement of the wearers arm on which the wristwatch is mounted. In this way, it is not necessary for the demand button 18 of FIG. 1 to be depressed for time to be displayed by the diodes. This makes it possible for the wristwatch wearer to ascertain the time even in those instances where it may not be convenient to press the demand button, each as when he is carrying something or in any other instance when the other hand is otherwise occupied.

In the preferred embodiment of the present invention, the arm-actuated switch 160 is used in combination with or in addition to the demand switch 132 actuated by pushbutton 18. FIG. 4 is a front or plan view of a modified watch 10 constructed in accordance with the present invention. The wristwatch of FIG. 4 is in all respects identical to the watch of FIG. 1 with the exception that the pushbutton 18 is eliminated. In this embodiment, the display is only actuated by a predetermined movement of the wearers arm and the watch is provided with a single display switch, such as the armactuated switch 160 as illustrated in FIG. 5. As can be seen, the only difference between the two embodiments is that the arm-actuated switch in the embodiment of FIGS. 4 and 5 is the sole switch for actuating the display, whereas in the embodiment of FIGS. 1-3, the arm-actuated switch is connected in parallel with the demand switch and the display may be operated by actuation of either one of the switches.

FIG. 6 illustrates one form which the arm-actuated switch 160 may take. FIG. 6 is a view of the watch case 12 with the back removed and the other parts of the watch omitted for the sake of clarity. Mounted within the watch case by suitable adhesive, such as epoxy or the like, is a miniature inertial switch, generally indicated in FIG. 6 at 162. The switch comprises an electrically conductive metal sleeve 164 in which is mounted a free-floating electrically conductive metal ball 166. Sleeve 164 is connected to an electrical lead 168. Passing through one end of sleeve 164 is a first electrical contact and passing through the other end of the sleeve is a second electrical contact 172. Contacts 170 and 172 are electrically insulated from sleeve 164 by any suitable means, such as for example by surrounding the portion of the contact passing through thee sleeve with a suitable electrical insulator (not shown). FIG. 7 shows the equivalent electrical circuit for the switch 162 and shows associated components, including a first flip-flop 174, a second flip-flop 176, a divider 178, and an NAND gate 180. Divider 178 is connected by a lead 182 to the binary divider chain forming the frequency converter 30 of FIG. 2 so that a 5 l2 Hz signal available from one of the stages of the frequency converter 30 is applied to divider 178 of FIG. 7; In operation, the inertial switch 162 is actuated by a short quick motion of the arm on which the watch is mounted in opposing directions in a plane essentially horizontal to the face of the watch. The round metal ball 166 in FIG. 6 first impacts against the round insulated contact 170 and the metal sleeve which contains the ball. With this impact, a closure signal is sent to the time circuit illustrated in FIG. 7. Before a preselected time has elapsed, for example, 500 milliseconds, the ball must complete the second circuit through insulated contact 172. In this way, both contacts have tobe closed by a deliberate swing of the arm within a preselected time interval. A wearer would rarely duplicate this particular motion sequence during routine daily activities.

Referring to FIG. 7, switch S2 comprising ball 166 and insulated contact 172 can be in any state but switch S2 and S1 (formed by the ball and contact 170) cannot both be closed at the same time because of the mechanical nature of the switch as illustrated in FIG. 6. Flipflop 176 can be at any state but flip-flop 174 is reset to receive an input from switch 81 by a reset pulse (R2) from divider 178 over lead 184. Nothing happens until switch S1 closes. When switch S1 closes, flip-flop 174 produces an output reset pulse (R1) which is applied by a lead 186 and a further lead 188 to flip-flop 176. The pulse on lead 188 resets flip-flop 176 and the pulse on lead 186 applied to counter 178 resets the counter. Reset pulse R1 at the output of flip-flop 174 is conditioned prior to entry into flip-flop 176 to get a short pulse. The 512 Hz input to the counter on lead 182 causes an output to occur on an output lead 190 from NAND gate after 2 pulses are counted which takes about 500 milliseconds. The 512 Hz signal is readily available from the frequency divider 30 of the watch and negative logic is used in FIG. 7 for consistency with the rest of the watch circuit. If switch S2 is closed before the 500 millisecond limit, the other necessary signal to cause an output pulse from NAND gate 180 is present. If switch S2 does not close within 500 milliseconds after the closure of switch S1, counter 178 will not cause a NAND gate output, but merely resets flip-flop 174. The output 190 from NAND gate 180 triggers the display circuit in the same manner as momentary closure of the demand switch 132 so that the hours and minutes of time are displayed for a predetermined period, such as l and 1/4 seconds. The construction shown in FIGS. 6 and 7 is fully compatible for use in addition to the demand switch as illustrated in FIG. 3 or may be used without a demand switch as illustrated in the circuit of FIG. 5. In both cases, the construction of FIGS. 6 and 7 constitutes the arm-responsive switch 160, generally illustrated in FIGS. 3 and 5.

FIG. 8 illustrates a modified construction for the arm-responsive switch 160 of FIG. 3 or FIG. 5. In FIG. 8, the arm-responsive switch, generally indicated at 192, takes the form of a simple force-actuated mechanical switch. Force switch 192 is mounted on the side of the watch case 12 and is a simple single-pole singlethrow switch comprising a flexible diaphragm 194 carrying a movable switch contact 196 and a stationary or fixed contact 198 mounted in the sidewall of the watch case 12. Again, switch 192 is constructed so that it is actuated by a deliberate and somewhat unconventional movement of the watch bearer which is completely independent of the arm or hand of the wearer opposite that on which the watch is mounted. In the embodiment illustrated in FIG. 8, the switch is contained inside the sealed flexible diaphragm 194 and an upward movement of the hand in a direction perpendicular to the plane of the watch face causes the movable contact 196 to be forced along with the diaphragm into engagement with the fixed contact 198 by the lower back side of the hand upon which the wristwatch is mounted. That is, the watch is placed in the conventional manner on the wearers wrist but is oriented so that the position 192 faces forward, i.e., toward the wearers hand. With the watch worn in the normal upward facing position, a backward flexure of the wrist causes the lower back side of the hand to engage the diaphragm 194 to close the contacts and operate the switch. With this construction, the switch may be held closed as long as the wearer desires, i.e., as long as his wrist remains flexed, and the switch 192 functions in the exact same manner as the pushbutton switch 132.

FIG. 9 shows a further embodiment of the switch 160 of FIGS. 3 and 5. In FIG. 9, the switch,indicated at 200, takes the form of a magnetic switch mounted by epoxy or other suitable adhesive on the inside of the case 12, which case is made of nonmagnetic material. By way of example only, switch 200 may be a magnetic reed switch of the type shown and described in copending US Pat. application Ser. No. l38,557. This switch is preferably mounted close to the inside surface of the watch case so that it may be actuated by bringing a permanent magnet close to the outside of the watch case adjacent the locations of the reed switch 200 so that the switch is operated by the magnetic field from a permanent magnet passing through the watch case. Again, switch 200 acts in the same manner as the demand switch 132 and can be held closed as long as possible. In order to obtain arm-responsive operation, the permanent magnet is attached to or made part of the wearers clothing. In the preferred embodiment, a permanent magnet is embedded in the buckle of the wearers belt. When the wearer wishes to observe the time, he simply draws his arm on which the watch is mounted into contact with or close proximity to his belt buckle so that the permanent magnet in the belt buckle operates the switch 200 to display time. Again, the time didplay is independent of the wearers other arm and requires a fairly unconventional movement or bringing of the watch into a fairly unconventional position, such as one which would not be experienced during normal routine functions.

FIG. 10 shows a further modified construction for the armresponsive switch 160. In the embodiment of FIG. 10, the switch, indicated by the reference numeral 202, is responsive to capacitance and includes a capacitor 204. The capacitor is indicated in dashed lines in FIG. 10 to indicate that it is mounted on the outside surface of the watch case 12 where it is normally away from or remote from the wearers wrist. The switch is actuated by a change in capacitance with the switch being sensitive enough to be actuated by a change in ambient capacitance brought about by moving the watch on which the switch is mounted away from the wearers skin into proximity with the body of the wearer. As an alternative to change in capacitance, the circuit can be made responsive to change in resistance if desired and the electrical circuit for either a variable capacitance, variable resistance, or a switch combining both is illustrated in FIG. 11. In this circuit, the capacitor 204 is connected between ground 206 and a complementary MOS transistor switch 208. Connected in series between ground and the positive side of the power supply of the battery with capacitor 204 is a resistor 210. A change in either capacitance or resistance or both causes the complementary MOS switch 208 to change state producing an output on lead 212 to energize the display in the manner previously described. The change in resistance can, for example, be brought about by contact with the bare skin of the wearer. Other more complicated circuits can be used, including sensing the detuning of a tuned oscillator circuit by bringing body capacitance into the circuit and completing a circuit through the introduction of normally available body moisture. Other arrangements for varying either capacitance, resistance, or both, are readily apparent.

It is apparent from the above that the present invention provides an improved solid state wristwatch construction and, more particularly, one which incorporates a display actuating switch which is responsive to a predetermined movement of the wearers arm. In all instances, the arm-responsive switch may be used by itself or in conjunction with a demand switch. It is provided to make it possible to display time without necessitating any operation by the wearers other hand so that the other hand is free for carrying packages or other uses as may be desired. In all instances, the armresponsive switch is constructed and/or positioned so that it is actuated only by a deliberate and relative unconventional movement on the part of the wearer. This assures that the watch display will not be inadvertently actuated too many times so as to cause an undue drain on the watch battery.

In some embodiments, the arm-actuated switch produces only a inpulse so that only the minutes and seconds of time are displayed for a preprogrammed duration, such as l and H4 seconds. In other embodiments,

the arm-responsive switch may be actuated as long as the wearer desires so that the seconds of time are also displayed. It is apparent that different delays may be programmed into the watch if it is desired that time be automatically displayed for a longer period and it is further apparent that instead of displaying only hours and minutes in response to an electrical impulse, additional display stations may be provided so that hours, minutes and seconds may be automatically displayed for a predetermined length of time.

in the preferred embodiment, the electro-optical display elements take the form of light-emitting diodes. However, it is understood that the display can assume any one of several forms. For example, the electrooptical display may be formed using such well known devices as miniature incandescent bulbs, other types of light-emitting diodes, or the well known liquid crystals, as well as lesser known devices, such as ferro electric crystals or electroluminescent displays and others.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States Letters Patent is:

l. A wristwatch comprising an electro-optical time display, an electrical power supply terminal for energizing said time display from a power supply, and an armresponsive inertial switch coupling said power supply terminal to said display whereby said display is energized upon a predetermined movement of a wearers arm upon which said wristwatch is mounted.

2. A wristwatch according to claim 13 comprising first and second flip-flops, a first of said contacts being coupled to the input of said first flip-flop, a second of said contacts being coupled to the input of said second flip-flop, and a logic circuit coupled to said flip-flops for producing an output signal in response to sequential engagement of said contacts by said ball.

3. A wristwatch according to claim 2 including a time delay circuit coupling the output of said first flip-flop to said logic circuit. 1

4. A wristwatch according to claim 3 wherein said time delay circuit comprises a binary counter.

5. A wristwatch according to claim 4 wherein said logic circuit comprises a NAND gate.

6. A wristwatch according to claim 1 including a second switch coupling said power supply to said display, said second switch being operable by the other hand of the wearer.

7. A wristwatch comprising a watch case, timekeep ing means in said case including a solid state electronic circuit and an electro-optical digital time display, an electrical power supply terminal in said case for energizing said display from a power supply, and an inertial switch carried by said case coupling said power supply terminal to said display, said switch being operative in response to a predetermined movement of the arm of a wearer.

8. A wristwatch according to claim 7 wherein said display comprises a plurality of light-emitting diodes.

9. A wristwatch according to claim 7 wherein said solid state electronic circuit comprises a crystal oscillator, a divider coupled to the output of said oscillator, and a display actuator coupling said divider to said display.

10. A wristwatch according to claim 7 including a watch battery in said case coupled to said terminal.

11. A wristwatch according to claim 7 including a pushbutton switch mounted on said watch case, said pushbutton switch coupling said power supply terminal to said display.

12. A wristwatch according to claim 11 wherein said arm-responsive switch and said pushbutton switch are connected in parallel with each other.

13. A wristwatch according to claim 7 wherein said switch comprises a conductive sleeve, a conductive ball in said sleeve, and a pair of spaced electrical contacts in said sleeve whereby upon predetermined movement said ball successively completes a circuit between said sleeve and first one said contact and then the other of said contacts.

mm x0. 3,742,699 t trnlglxulrl2l Inventofls); John M Bergey It is certifii ed that error appears in the EliO'VQ-idfifltlfllEH] patent and that said Letters Patent are hereby corrected as shown below:

Column '3, line 6, "over" should read --overcome--. Column 5, line 49, "cathods" should read --cathodeS--;

line 51, "strobbi'ng" should read --strobing--.

Column 6, line 63, "of" should read ---or---.

Column 7, line 10., "dividier" should read -divider--; line 53, "each" should read --s uch-.

Column- 8, line 23, "thee" should read --the--.

Column 9,- line 29, "bearer" should read --wearer--; line 40, "position" should read --switch-- line 61, "locations" should read --location-- Column 10, line 7, "did-" should read disline 59, "relative" should read --relatively-.-; line 66, inpulse" should read --impu1se--.

Signd and sealed this 5th day of. March 197A.

(SEAL) Attest:

EDWARD M.FLETCHER,JH. C MARSHALL. D-ANN Attesting Offlcer I Commissioner of Patents F ORM PO-105O (10-59) patent No. 3,742, 9 bated July 3, 1973 Inventofls) John N. Bergey It is certified that error appears in the awo've-identiffied patent. and that said Letters Patent are hereby corrected as shown helm-1:

Columh '3 line 6, "over" should read --overcome--. Column' 5, line 49; "cathods" should read "cathodes"; line 51, "strobbi'ng" should read- --strobirig--.

Column 6, line 63, "of" should read --or--. Column 7, line 10., "dividier" should read -divide'r--; line 53, "each" should read --s uch--.

Column 8; line 23, "thee" should read --the-. Column 9,- line 29, "bearer" should read ---wearer--; line 40, "position" should read "switchline 61, "locations" should read --location-- q Columr 1 10', line 7, "did-" should read disline 59, "relative" should read --relatively-;-; line 66, inpulse" should read --impulse--.

Signed and sealed this 5th day of. March 19714..

(SEAL) Attest: EDWARD M.FLET:CHER,JR. C MARSHALL. D'ANN Attesting Commissioner of Patents 

1. A wristwatch comprising an electro-optical time display, an electrical power supply terminal for energizing said time display from a power supply, and an arm-responsive inertial switch coupling said power supply terminal to said display whereby said display is energized upon a predetermined movement of a wearer''s arm upon which said wristwatch is mounted.
 2. A wristwatch according to claim 13 comprising first and second flip-flops, a first of said contacts being coupled to the input of said first flip-flop, a second of said contacts being coupled to the input of said second flip-flop, and a logic circuit coupled to said flip-flops for producing an output signal in response to sequential engagement of said contacts by said ball.
 3. A wristwatch according to claim 2 including a time delay circuit coupling the output of said first flip-flop to said logic circuit.
 4. A wristwatch according to claim 3 wherein said time delay circuit comprises a binary counter.
 5. A wristwatch according to claim 4 wherein said logic circuit comprises a NAND gate.
 6. A wristwatch according to claim 1 including a second switch coupling said power supply to said display, said second switch being operable by the other hand of the wearer.
 7. A wristwatch comprising a watch case, timekeeping means in said case including a solid state electronic circuit and an electro-optical digital time display, an electrical power supply terminal in said case for energizing said display from a power supply, and an inertial switch carried by said case coupling said power supply terminal to said display, said switch being operative in response to a predetermined movement of the arm of a wearer.
 8. A wristwatch according to claim 7 wherein said display comprises a plurality of light-emitting diodes.
 9. A wristwatch according to claim 7 wherein said solid state eleCtronic circuit comprises a crystal oscillator, a divider coupled to the output of said oscillator, and a display actuator coupling said divider to said display.
 10. A wristwatch according to claim 7 including a watch battery in said case coupled to said terminal.
 11. A wristwatch according to claim 7 including a pushbutton switch mounted on said watch case, said pushbutton switch coupling said power supply terminal to said display.
 12. A wristwatch according to claim 11 wherein said arm-responsive switch and said pushbutton switch are connected in parallel with each other.
 13. A wristwatch according to claim 7 wherein said switch comprises a conductive sleeve, a conductive ball in said sleeve, and a pair of spaced electrical contacts in said sleeve whereby upon predetermined movement said ball successively completes a circuit between said sleeve and first one said contact and then the other of said contacts. 